#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
typedef char X;
typedef struct BTNode {
	X data;
	struct BTNode* left;
	struct BTNode* ringth;
}BT;
void PrevOrder(BT* root);
void InOrder(BT* root);
void PostOrder(BT* root);
